In Latin grammar, the ablative case (cāsus ablātīvus) is one of the six cases of nouns.Traditionally, it is the sixth case (cāsus sextus, cāsus latīnus).It has forms and functions derived from the Proto-Indo-European ablative, instrumental, and locative.It expresses concepts similar to those of the English prepositions from; with, by; and in, at.

Latin declension is the set of patterns according to which Latin words are declined, or have their endings altered to show grammatical case, number and gender.Nouns, pronouns, and adjectives are declined (verbs are conjugated), and a given pattern is called a declension.There are five declensions, which are numbered and grouped by ending and grammatical gender.